Lubricant



United States Patent 3,215,707 LUBRICANT Rudolph J. Reuse, Gates Mills,Ohio, assignor to The Lubrizol Corporation, Wicklifie, Ohio, acorporation of Ohio No Drawing. Original application June 7, 1960, Ser.No. 34,390. Divided and this application Mar. 31, 1964, Ser. No. 356,050

9 Claims. (Cl. 260326.3)

This application is a division of copending application Ser. No. 34,390filed June 7, 1960.

This invention relates to hydrocarbon-substituted succinic acids andderivatives thereof. In the more particular sense it relates to animproved process for the preparation of such compounds.

Hydrocarbon-substituted succinic acid compounds are useful for a widevariety of purposes. For example, the acids and the anhydrides areuseful as rust-inhibiting agents in aqueous and hydrocarbon oilcompositions; the esters, as synthetic lubricating oils, plasticizers,and paint vehicles; the metal and ammonium salts, as dispersing agents.The methods heretofore known in the art for preparing such compoundsusually involve the alkylation of maleic anhydride with an olefinichydrocarbon or a halogen-substituted hydrocarbon to produce analkenylsubstituted succinic anhydride. The anhydride so obtained may beconverted to the corresponding acid, ester, amide, salt, or a likederivative by treatment with water, alcohols, phenols, amines, or basicmetal compounds. It is likewise known in the art thatalkenyl-substituted succinic acid compounds are obtainable directly frommaleic acid, esters, or salts by treatment of the maleic compound withan olefinic or halogen-containing hydrocarbon. The alkenyl-succinic acidcompounds may also be converted to the corresponding alkyl-substitutedsuccinic acid compounds by hydrogenation.

The commercial usefulness of the processes for preparinghydrocarbon-substituted succinic compounds depends to a large measureupon the ease with which the processes can be carried out and also uponthe properties characterizing the products obtained therefrom. In thisrespect it should be pointed out that the alkylation of maleic anhydridewith an olefinic hydrocarbon is very time-consuming and furthermorelimited in its applicability to relatively low molecular weight olefinichydrocarbon reactants, i.e., those having less than about 12-15 carbonatoms. The higher molecular weight olefinic hydrocarbons are apparentlynot sufficiently reactive with maleic anhydride to be useful as thealkylating agent. Thus, high molecular Weight hydrocarbon-substitutedsuccinic acid compounds are almost invariably prepared by reactingmaleic anhydride with a halogenated high molecular weight hydrocarbonreactant. While this latter reaction is used commercially, it hasseveral drawbacks. A principal drawback is that it requires a first stepof halogenating a hydrocarbon and a second step of reacting maleicanhydride with the halogenated hydrocarbon so obtained. Both steps areslow so that the overall process is extremely time-consuming. Anotherserious drawback is that the products obtained by this two-step processare usually dark in color. It will be readily appreciated that a darkcolored product is much less appealing than a similar but light coloredproduct. Consequently the usefulness of high molecular weighthydrocarbon-substituted succinic acid compounds has not been sowidespread as their properties have indicated.

It is apparent, therefore, that a more eificient process or one which iscapable of producing light colored hydrocarbon-substituted succinic acidcompounds will greatly enhance the commercial usefulness of suchproducts.

3,215,707 Patented Nov. 2, 1965 Accordingly it is a principal object ofthis invention to provide a more efficient process for preparinghydrocarbon substituted succinic acid compounds than has heretofore beenknown in the art.

It is also an object of this invention to provide a process forpreparing light colored acylated polyamines derived fromhydrocarbon-substituted succinic acid compounds.

It is another object of this invention to provide an efficient processfor preparing light colored acylated polyamines derived from relativelyhigh molecular weight hydrocarbon-substituted succinic acid compounds.

These and other objects are obtained in accordance with this inventionby providing a process for preparing hydrocarbon-substituted succinicanhydrides which comprises preparing a mixture of an olefin polymer andmaleic anhydride, and contacting said mixture at a temperature aboveabout 140 C. with at least about one mole of chlorine for each mole ofmaleic anhydride. The product of the above process, as indicated before,is a hydrocarbon-substituted succinic anhydride, but it is not yetestablished whether the hydrocarbon radical is a saturated radical orone having olefinic linkages. The mechanism by which the product isformed is likewise not known. It is known, however, that the process isdifferent from one in which the olefin polymer is first chlorinated andthe chlorinated polymer is then allowed to react with maleic anhydrideunder similar reaction conditions. The latter two-step process requiresa considerably lengthier reaction time and results in products which aremuch darker in color. Also, if the olefin polymer is to be chlorinatedfirst, the chlorination temperature should not be allowed to exceedabout C. Higher temperatures are known to cause dechlorination and thusresult in products having little or no chlorine. In this respect, itwill be noted that the temperature for the process of this invention isconsiderably above the maximum temperature suitable for preparingchlorinated olefin polymers.

To carry out the process of this invention, it is critically importantthat the chlorine be introduced into the reac tion zone after the olefinpolymer has been thoroughly mixed with maleic anhydride. If the chlorineis allowed to come into contact with the olefin polymer prior to theintroduction of maleic anhydride, chlorination of the polymer will takeplace and the advantageous results of this invention will not beobtained. The rate of introduction of the chlorine is not critical.Ordinarily, for maximum utilization of the chlorine used, the rateshould be about the same as the rate of consumption of chlorine in thisreaction.

The minimum temperature at which the reaction of the above process takesplace at a reasonable rate is about C.; hence, the minimum temperatureat which the process should be carried out is in the neighborhood of 140C. The preferred temperatures usually range between about C. and about220 C. Higher temperatures such as 250 C. or even higher may be used butusually with little advantage. The upper limit of the usable temperatureis determined primarily by the decomposition point of the components inthe reaction mixture.

The stoichiometry of the reaction involved in the herein-describedprocess requires approximately equi-molar amounts of the maleicanhydride and the chlorine used. For practical considerations, however,a slight excess, usually in the neighborhood of 20-30%, of chlorine ispreferred in order to offset any accidental loss of this gaseousreactant from the reaction mixture. Still greater amounts of chlorinemay be used but they do not appear to produce any noticeable benefits.

The relative amounts of the olefin polymer and maleic anhydride willvary according to the proportion of the succinic anhydride radicalsdesired in the product. Thus, for each mole of the polymer employed, oneor more moles of maleic anhydride may be used depending upon whether oneor more succinic anhydride radicals are to be incorporated in eachpolymer molecule. In general, the higher the molecular weight of thepolymer, the greater the proportion of maleic anhydride which may beused. On the other hand, when a molar excess of the polymer reactant isused, the excess polymer will simply remain in the product as a diluentwithout any adverse effect As indicated previously the process of thisinvention is applicable to the preparation of hydrocarbon substitutedsuccinic anhydride from olefin polymers. The olefin polymers includeprincipally the homopolymers and interpolymers of lower mono-olefin,i.e., ethylene, propene, isobutene, and n-butene. Interpolymers of theaboveillustrated lower mono-olefins with interpolymerizable highermono-olefins or diolefins such as hexene, cyclohexene, butadiene,isoprene, chloroprene, etc., are likewise contemplated for use herein,provided that the lower mono-olefin units comprise at least 90-95% byweight of the polymer. The interpolymers may be exemplified bycopolymers of 99% of isobutene with 1% of butadiene, copolymers of 95%of isobutene with of styrene, copolymers of 98% of propene with 2% ofpiperylene, terpolymers of 97% of isobutene with 1% of piperylene and 1%of propene, etc. For the most part, polymers of isobutene are preferredfor reasons of their ready availability and the particular utility ofthe products obtained therefrom. The molecular weights of the polymerscontemplated for use herein may vary within broad limits such as fromabout 100 to about 50,000 or even higher. Polymers having intermediatemolecular Weights, i.e., 250- 3000 are especially useful.

The following examples illustrate the process of this invention ingreater detail. The ASTM color rating re ported in the examples is anumerical index of the color of a sample as determined by visualcomparison of the 15% solution by weight (in kerosene) with a series ofdifferent colored standards ranging from light lemoncolored standard(rating of 1) to deep red-colored standard (rating of 8). Examples 2, 4and 5 illustrate the prior art processes, all of which requireconsiderably lengthier reaction time to produce the desired productsthan the process of this invention illustrated in Examples 1 and 3. Itwill be noted also that the product of Example 2 has an ASTM colorrating of 8 whereas an otherwise similar product prepared by the processof this invention (Example 1) has an ASTM color rating of 4.

Example 1 Acid number 100 Percent chlorine 0.4 ASTM color 4 Example 2 Apolyisobutene of Example 1 is chlorinated to a product having a chlorinecontent of 4.3% prepared by passing 72 parts (by weight) of chlorineinto 750 parts of the polymer at 100 C. at the maximum rate permitted bythe chlorination reaction (requiring 8 hours). A mixture of 750 parts ofthe chlorinated polyisobutene and 85 parts of maleic anhydride is heatedat 190 C. for 1 hour and then at 200210 C. until all of the maleicanhydride used is consumed (requiring 10 hours). found to have thefollowing analyses:

The residue is Example 3 A mixture of 500 parts (by weight) (5.1 moles)of maleic anhydride and 1080 parts (6.4 moles) of propylene tetramer isheated to 175 C., and 385 parts (5.5 moles) of chlorine is introducedbeneath the surface of the mixture at 175 -205 C. within a period of 4.5hours. The mixture is then purged with nitrogen for 30 minutes at 180205C. The residue is then heated at 230300 C. whereupon 1122 parts (92% ofthe theoretical yield) of the propylene tetramer substituted succinicanhydride is collected as the distillate. The distilled anhydride isfound to have the following analyses:

Percent chlorine Acid number Example 4 Example 5 Chlorine is introducedbeneath the surface of 1670 parts (10 moles) of propylene tetramer at6090 C. at a rate of 40 parts/hour until 300 parts of chlorine hasincorporated into the mixture (requiring 20 hours). The mixture iswashed with aqueous NaHCO and water and then dried and distilled to give285 parts of a monochlorine substituted propylene tetramer. A mixture of660 parts (3.14 moles) of the mono-chlorine substituted propylenetetramer and 294 parts (3 moles) of maleic anhydride is heated to 170 C.in 5 hours and at 170- 175 C. for 5 more hours. The mixture is thenheated at C./ 18 mm. Hg and filtered. The filtrate, weighing 690 parts(74% of the theoretical yield) is found to have the following analyses:

Percent chlorine 2.7 Acid number 323 Example 6 A propylene tetramersubstituted succinic anhydride molecular weight of 1000 is converted toa substituted succinic anhydride by reaction with maleic anhydride andchlorine at C. according to the following stepwise procedure: mixingwith 50 parts of maleic anhydride and followed by bubbling into themixture 35 parts of chlorine in 1 hour; mixing with an additional 50parts of maleic anhydride and followed by bubbling into the mixture 35parts of chlorine in 1 hour; mixing with an additional 50 parts ofmaleic anhydride and followed by bubbling into the mixture 35 parts ofchlorine in 1 hour; mixing with an additional 50 parts of maleicanhydride and followed by bubbling into the mixture 35 parts of chlorinein 1 hour; mixing with an additional 25 parts of maleic anhydride andfollowed by bubbling into the mixture 17.5 parts of chlorine in 0.5hour; mixing with an additional 28 parts of maleic anhydride andfollowed by bubbling into the mixture 32.5 parts of chlorine in 1 hour;and mixing with an additional 22 parts of maleic anhydride and followedby bubbling into the mixture 27.5 parts of chlorine in 1 hour. Theanhydride product obtained is found to have the following analyses:

Percent chlorine 0.5 Acid number 97.5 ASTM color 2-3 The productsobtained by the process of this invention are useful for a large varietyof purposes well known in the art. For example, the relatively lowmolecular weight (e.g., 150300) hydrocarbon-substituted anhydrides areknown to be effective as rust-inhibiting additives in gasolines, fueloils, cutting oils, automotive engine lubricants, etc. When used in suchcompositions only a very small amount usually in the neighborhood of0.001O.5% by weight of the additive is sufficient to produce the desiredresult. A specific example illustrating such use is a catalyticallycracked Number 2 light fuel oil to which there is added 0.02% by weightof the product of Example 3.

The higher molecular weight hydrocarbon-substituted succinic anhydridesare useful, for example, as intermediates for the preparation of esterderivatives which are useful as synthetic lubricating oils, paintvehicles, and plasticizers. The metal salts, amides, and ammonium saltsof such anhydrides are useful as dispersing agents in hydrocarbon oilcompositions. When used as dispersing agents, the salts or amides aregenerally employed in amounts from 0.5-5 more often in the neighborhoodof 1-3%, by weight of the hydrocarbon oil composition.

A particularly useful class of additives for hydrocarbon oils compriseacylated polyamines prepared by reacting the hydrocarbon-substitutedsuccinic anhydride of this invention with an ethylene amine underdehydrating conditions.

The term ethylene amine is used in a generic sense to denote a class ofpolyamines conforming for the most part to the structure mN or-M HNII).H R

in which x is an integer and R is a low molecular weight alkyl radicalor hydrogen. Thus it includes for example, ethylene diamine, diethylenetriarnine, triethylene tetramine, tetraethylene pentamine, pentaethylenehexamine, etc. These compounds are discussed in some detail under theheading Ethylene Almines in Encyclopedia of Chemical Technology, Kirkand Othrner, Vol. 5, pages 898-905, Interscience Publishers, New York(1950). Such compounds are prepared most conveniently by the reaction ofethylene dichloride with ammonia. This process results in the productionof somewhat complex mixtures of ethylene amines, including cycliccondensation products such as piperazines and these mixtures find use inthe process of this invention. On the other hand, quite satisfactoryproducts may be obtained also by the use of pure ethylene amines. Anespecially useful ethylene amine, for reasons of economy as well aseffectiveness as a dispersant, is a mixture of ethylene amines preparedby the reaction of ethylene chloride and amimonia, having a compositionwhich corresponds to that of tetraethylene pentamine. This is availablein the trade under the trade name Polyamine H.

It has been noted that at least one-half of a chemical equivalent amountof the ethylene amine per equivalent of substituted succinic anhydridemust be used in the process to produce a satisfactory product withrespect to dispersant properties and generally it is preferred to usethese reactants in equivalent amounts. Amounts up to 2.0 chemicalequivalents (per equivalent of substituted succinic anhydride) have beenused with success, although there appears to be no advantage attendantupon the use of more than this amount. The chemical equivalency of theethylene amine reactant is based upon the nitrogen content, i.e., onehaving four nitrogens per molecule has four equivalents per mole.

The reaction of the process involves a splitting out of water and thereaction conditions are such that this water is removed as it is formed.Presumably the first principal reaction that occurs, following saltformation, is the formation of a half amide CHZOO followed then by saltformation R-OHC 0 OH rt-onooomr m HrNR (g mo ONHR Hi0 ONHR and involvingfinally dehydration of this salt to form the product R-CHOOHslGRRCHCONHR H 0 ONHR HZCONHR The first two of these reactions appear totake place spontaneously (when a substituted succinic anhydride is used)upon mixing, but the third requires heating. Temperatures within therange of about C. to about 200 C. are satisfactory, and within thisrange it is preferred to use a reaction temperature of from about C. toabout 160 C. A useful method of carrying out this step is to add sometoluene to the reaction mixture and to remove the water by azeotropicdistillation. As indicated before there is also some imide-formation.

The following example illustrates the process which may be used toprepare the acylated polyamines.

Example 7 To a mixture of 241 parts (by weight) of the substitutedsuccinic anhydride of Example 6 and 63 parts of mineral oil, there areadded 4.25 parts of diethylene triamine and 12.75 parts oftriethylenetetramine at 65-85 C. in 2 hours. The mixture is heated to C.in 5 hours, blown with nitrogen for 5 hours at 150-155 C., and filtered.The filtrate is found to have the following analyses:

Percent nitrogen 2.04

Neutralization No 1 31 ASTM color 2-3 Basic.

Further illustration of the usefulness of the acylated polyamines ofthis invention as dispersants in motor oils was gained from a modifiedversion* of the CRC-EX-3 Engine Test. This test is recognized in thefield as an important test by which lubricants can be evaluated for useunder light-duty service conditions. In this particular test thelubricant is used in the crankcase of a 1954 6-cylinder ChevroletPowerglide engine for 144 hours under recurring cycling conditions, eachcycle consisting of:

2 hours at an engine speed of 500125 r.p.m. under zero load at an oilsump temperature of 100l25 F.; airfuel ratio of 10:1;

2 hours at an engine speed of 2500125 r.p.m. under a load of 40brake-horsepower at an oil sump temperature of l60-170 F.; air-fuelratio of 16:1;

2 hours at an engine speed of 2500:25 r.p.m. under a load of 40brake-horsepower at an oil sump temperature of 240250 F.; air-fuel ratioof 16:1.

After completion of the test, the engine is dismantled and various partsof the engine are examined for engine deposits. The lubricant dispersantaddition agent is then rated according to (1) the extent of pistonring-filling, (2) the amount of sludge formed in the engine (on a scaleof 800, 80 being indicative of no sludge and 0 being indicative ofextremely heavy sludge), and (3) the total amount of engine deposits,i.e., sludge and varnish,

*Ordiuarily this test lasts for 96 hours.

formed in the engine (on a scale of 100-0, 100 being indicative of nodeposits and being indicative of ex tremely heavy deposits).

A SAE20 lubricating oil to which there have been added 0.5% (by weightof the product of Example 7, 0.076% of phosphorus as a zincdialkylphosphorodithioate, 0.003% of a polyalkylsiloxane anti-foamagent, and 0.3% of sulfate ash as a basic barium salt of an organicphosphorus acid prepared by the reaction of a polyisobutene having amolecular weight of 1000 with phosphorus trichloride and an alkyl phenolis found by this engine test to give the following result: Piston RingFilling2%; Sludge Rating74.7; Total Deposit Rating92.4.

What is claimed is:

1. A process for preparing acylated polyarnines comprising preparing amixture of an aliphatic polymer of a lower mono-olefin and maleicanhydride; contacting said mixture at a temperature above about 140 C.and below the decomposition point of said mixture with about one mole ofchlorine for each mole of maleic anhydride to form a substitutedsuccinic anhydride; mixing said substituted succinic anhydride with atleast about one-half an equivalent of an ethylene polyamine having thestructure wherein R is selected from the class consisting of hydrogenand lower alkyl and x has an average value ranging from 1 to about 6;and heating said mixture at a temperature above about 80 C. and belowthe decomposition point of said mixture to effect acylation and removethe water formed thereby.

2. The process of claim 1 wherein the ethylene polyamine is apolyethylene polyarnine having about five amino groups.

3. The process of claim 1 wherein the aliphatic polymer is a polymer ofisobutene.

4. The process of claim 1 wherein the aliphatic polymer is aninterpolymer of at least about 90% by weight isobutene and up to about10% by weight a di-olefin.

5. The process of claim 1 wherein the aliphatic polymer is apolyisobutene having a molecular weight within the range of from about500 to about 3,000.

6. A process for preparing acylated polyamines comprising preparing amixture of a polyisobutene having a molecular weight of from about 500to about 3,000 and maleic anhydride, contacting said mixture at atemperature of from about 140 C. to about 250 C. with about one mole ofchlorine for each mole of maleic anhydride to form a substitutedsuccinic anhydride, mixing said substituted succinic anhydride with fromabout one-half 8 to about two equivalents of a polyethylene polyaminehaving up to about six amino groups, and heating said mixture at atemperature above about C. and below the decomposition point to efiectacylation and remove the water formed thereby.

7. A process for preparing acylated polyamines comprising preparing amixture of a polyisobutene having a molecular weight of about 1,000 andabout one mole of maleic anhydride, contacting said mixture at atemperature from about 160 C. to about 220 C. with about one mole ofchlorine to form a substituted succinic anhydride, mixing saidsubstituted succinic anhydride with from about one-half to about twoequivalents of tetraethylene pentamine, and heating said mixture at atemperature of from about C. to about 200 C. to effect acylation andremove the water formed thereby.

8. A process for preparing acylated polyamines comprising preparing amixture of a polyisobutene having a molecular weight of about 1,000 andabout one mole of maleic anhydride, contacting said mixture at atemperature from about C. to about 220 C. with about one mole ofchlorine to form a substituted succinic anhydride, mixing saidsubstituted succinic anhydride with from about one-half to about twoequivalents of ethylene diamine, and heating said mixture at atemperature of from about 100 C. to about 200 C. to effect acylation andremove the water formed thereby.

9. A process for preparing acylated polyamines comprising preparing amixture of a polyisobutene having a molecular weight of about 1,000 andabout one mole of maleic anhydride, contacting said mixture at atemperature from about 160 C. to about 220 C. with about one mole ofchlorine to form a substituted succinic anhydride, mixing saidsubstituted succinic anhydride with from about one-half to about twoequivalents of a mixture of diethylene triamine and triethylenetetramine, and heating said mixture at a temperatureof from about 100 C.to about 200 C. to effect acylation and remove the water formed thereby.

References Cited by the Examiner UNITED STATES PATENTS 2,490,744 12/49Trigg et al 25251.5 X 2,604,451 7/ 52 Rocchini 252-51.5 3,018,250 1/62Anderson et al. 2525l.5

FOREIGN PATENTS 1,254,094 1/ 61 France. 1,265,086 5/61 France.

922,831 4/63 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

1. A PROCESS FOR PREPARING ACYLATED POLYAMINES COMPRISING PREPARING A MIXTURE OF AN ALIPHATIC POLYMER OF A LOWER MONO-OLEFIN AND MALEIC ANHYDRIDE: CONTACTING SAID MIXTURE AT A TEMPERATURE ABOVE ABOUT 140*C. AND BELOW THE DECOMPOSITION POINT OF SAID MIXTURE WITH ABOUT ONE MOLE OF CHLORINE FOR EACH MOLE OF MALEIC ANHYDRIDE TO FORM A SUBSTITUTED SUCCINIC ANHYDRIDE; MIXING SAID SUBSTITUTED SUCCINIC ANHYDRIDE WITH AT LEAST ABOUT ONE-HALF AN EQUIVALENT OF AN ETHYLENE POLYAMINE HAVING THE STRUCTURE 